aboutsummaryrefslogtreecommitdiff
path: root/drivers/i2c/chips/lm83.c
blob: a49008b444c8ef483f3e6ec933578c3a9e57e240 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
/*
 * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2005  Jean Delvare <khali@linux-fr.org>
 *
 * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
 * a sensor chip made by National Semiconductor. It reports up to four
 * temperatures (its own plus up to three external ones) with a 1 deg
 * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
 * from National's website at:
 *   http://www.national.com/pf/LM/LM83.html
 * Since the datasheet omits to give the chip stepping code, I give it
 * here: 0x03 (at register 0xff).
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/i2c-sensor.h>
#include <linux/hwmon-sysfs.h>

/*
 * Addresses to scan
 * Address is selected using 2 three-level pins, resulting in 9 possible
 * addresses.
 */

static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
					0x29, 0x2a, 0x2b,
					0x4c, 0x4d, 0x4e,
					I2C_CLIENT_END };
static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };

/*
 * Insmod parameters
 */

SENSORS_INSMOD_1(lm83);

/*
 * The LM83 registers
 * Manufacturer ID is 0x01 for National Semiconductor.
 */

#define LM83_REG_R_MAN_ID		0xFE
#define LM83_REG_R_CHIP_ID		0xFF
#define LM83_REG_R_CONFIG		0x03
#define LM83_REG_W_CONFIG		0x09
#define LM83_REG_R_STATUS1		0x02
#define LM83_REG_R_STATUS2		0x35
#define LM83_REG_R_LOCAL_TEMP		0x00
#define LM83_REG_R_LOCAL_HIGH		0x05
#define LM83_REG_W_LOCAL_HIGH		0x0B
#define LM83_REG_R_REMOTE1_TEMP		0x30
#define LM83_REG_R_REMOTE1_HIGH		0x38
#define LM83_REG_W_REMOTE1_HIGH		0x50
#define LM83_REG_R_REMOTE2_TEMP		0x01
#define LM83_REG_R_REMOTE2_HIGH		0x07
#define LM83_REG_W_REMOTE2_HIGH		0x0D
#define LM83_REG_R_REMOTE3_TEMP		0x31
#define LM83_REG_R_REMOTE3_HIGH		0x3A
#define LM83_REG_W_REMOTE3_HIGH		0x52
#define LM83_REG_R_TCRIT		0x42
#define LM83_REG_W_TCRIT		0x5A

/*
 * Conversions and various macros
 * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
 */

#define TEMP_FROM_REG(val)	((val) * 1000)
#define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
				 (val) >= 127000 ? 127 : \
				 (val) < 0 ? ((val) - 500) / 1000 : \
				 ((val) + 500) / 1000)

static const u8 LM83_REG_R_TEMP[] = {
	LM83_REG_R_LOCAL_TEMP,
	LM83_REG_R_REMOTE1_TEMP,
	LM83_REG_R_REMOTE2_TEMP,
	LM83_REG_R_REMOTE3_TEMP,
	LM83_REG_R_LOCAL_HIGH,
	LM83_REG_R_REMOTE1_HIGH,
	LM83_REG_R_REMOTE2_HIGH,
	LM83_REG_R_REMOTE3_HIGH,
	LM83_REG_R_TCRIT,
};

static const u8 LM83_REG_W_HIGH[] = {
	LM83_REG_W_LOCAL_HIGH,
	LM83_REG_W_REMOTE1_HIGH,
	LM83_REG_W_REMOTE2_HIGH,
	LM83_REG_W_REMOTE3_HIGH,
	LM83_REG_W_TCRIT,
};

/*
 * Functions declaration
 */

static int lm83_attach_adapter(struct i2c_adapter *adapter);
static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
static int lm83_detach_client(struct i2c_client *client);
static struct lm83_data *lm83_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */
 
static struct i2c_driver lm83_driver = {
	.owner		= THIS_MODULE,
	.name		= "lm83",
	.id		= I2C_DRIVERID_LM83,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= lm83_attach_adapter,
	.detach_client	= lm83_detach_client,
};

/*
 * Client data (each client gets its own)
 */

struct lm83_data {
	struct i2c_client client;
	struct semaphore update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	s8 temp[9];	/* 0..3: input 1-4,
			   4..7: high limit 1-4,
			   8   : critical limit */
	u16 alarms; /* bitvector, combined */
};

/*
 * Sysfs stuff
 */

static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm83_data *data = lm83_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
}

static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
			const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm83_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int nr = attr->index;

	down(&data->update_lock);
	data->temp[nr] = TEMP_TO_REG(val);
	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
				  data->temp[nr]);
	up(&data->update_lock);
	return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
			   char *buf)
{
	struct lm83_data *data = lm83_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
	set_temp, 4);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
	set_temp, 5);
static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
	set_temp, 6);
static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
	set_temp, 7);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
	set_temp, 8);
static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

/*
 * Real code
 */

static int lm83_attach_adapter(struct i2c_adapter *adapter)
{
	if (!(adapter->class & I2C_CLASS_HWMON))
		return 0;
	return i2c_detect(adapter, &addr_data, lm83_detect);
}

/*
 * The following function does more than just detection. If detection
 * succeeds, it also registers the new chip.
 */
static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
{
	struct i2c_client *new_client;
	struct lm83_data *data;
	int err = 0;
	const char *name = "";

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		goto exit;

	if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit;
	}
	memset(data, 0, sizeof(struct lm83_data));

	/* The common I2C client data is placed right after the
	 * LM83-specific data. */
	new_client = &data->client;
	i2c_set_clientdata(new_client, data);
	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &lm83_driver;
	new_client->flags = 0;

	/* Now we do the detection and identification. A negative kind
	 * means that the driver was loaded with no force parameter
	 * (default), so we must both detect and identify the chip
	 * (actually there is only one possible kind of chip for now, LM83).
	 * A zero kind means that the driver was loaded with the force
	 * parameter, the detection step shall be skipped. A positive kind
	 * means that the driver was loaded with the force parameter and a
	 * given kind of chip is requested, so both the detection and the
	 * identification steps are skipped. */

	/* Default to an LM83 if forced */
	if (kind == 0)
		kind = lm83;

	if (kind < 0) { /* detection */
		if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
		    & 0xA8) != 0x00) ||
		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
		    & 0x48) != 0x00) ||
		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
		    & 0x41) != 0x00)) {
			dev_dbg(&adapter->dev,
			    "LM83 detection failed at 0x%02x.\n", address);
			goto exit_free;
		}
	}

	if (kind <= 0) { /* identification */
		u8 man_id, chip_id;

		man_id = i2c_smbus_read_byte_data(new_client,
		    LM83_REG_R_MAN_ID);
		chip_id = i2c_smbus_read_byte_data(new_client,
		    LM83_REG_R_CHIP_ID);

		if (man_id == 0x01) { /* National Semiconductor */
			if (chip_id == 0x03) {
				kind = lm83;
			}
		}

		if (kind <= 0) { /* identification failed */
			dev_info(&adapter->dev,
			    "Unsupported chip (man_id=0x%02X, "
			    "chip_id=0x%02X).\n", man_id, chip_id);
			goto exit_free;
		}
	}

	if (kind == lm83) {
		name = "lm83";
	}

	/* We can fill in the remaining client fields */
	strlcpy(new_client->name, name, I2C_NAME_SIZE);
	data->valid = 0;
	init_MUTEX(&data->update_lock);

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(new_client)))
		goto exit_free;

	/*
	 * Initialize the LM83 chip
	 * (Nothing to do for this one.)
	 */

	/* Register sysfs hooks */
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp1_input.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp2_input.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp3_input.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp4_input.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp1_max.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp2_max.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp3_max.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp4_max.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp1_crit.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp2_crit.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp3_crit.dev_attr);
	device_create_file(&new_client->dev,
			   &sensor_dev_attr_temp4_crit.dev_attr);
	device_create_file(&new_client->dev, &dev_attr_alarms);

	return 0;

exit_free:
	kfree(data);
exit:
	return err;
}

static int lm83_detach_client(struct i2c_client *client)
{
	int err;

	if ((err = i2c_detach_client(client))) {
		dev_err(&client->dev,
		    "Client deregistration failed, client not detached.\n");
		return err;
	}

	kfree(i2c_get_clientdata(client));
	return 0;
}

static struct lm83_data *lm83_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm83_data *data = i2c_get_clientdata(client);

	down(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
		int nr;

		dev_dbg(&client->dev, "Updating lm83 data.\n");
		for (nr = 0; nr < 9; nr++) {
			data->temp[nr] =
			    i2c_smbus_read_byte_data(client,
			    LM83_REG_R_TEMP[nr]);
		}
		data->alarms =
		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
		    << 8);

		data->last_updated = jiffies;
		data->valid = 1;
	}

	up(&data->update_lock);

	return data;
}

static int __init sensors_lm83_init(void)
{
	return i2c_add_driver(&lm83_driver);
}

static void __exit sensors_lm83_exit(void)
{
	i2c_del_driver(&lm83_driver);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("LM83 driver");
MODULE_LICENSE("GPL");

module_init(sensors_lm83_init);
module_exit(sensors_lm83_exit);